1:9 heavy subsonic .223 Qs

[Hersh5317]

What is the heaviest bullet you have been able to stabilize in a 1:9 loaded to about 1k fps? If you are comfortable sharing the load data, please do so. I am curious to see as I had intended to build a fast twist Hornet for such applications, but was told it would be easier to do with a .223 due to brass life and availability. The heaviest/longest I have is 55 Vmax, but wonder if the 60 Vmax, or any of the 68/69 grainers would stabilize at subsonic speeds in my 22" 1:9.

[andyknaster]

I'm trying 4gr of Trail Boss using the basically the following configuration:
https://uploads.tapatalk-cdn.com/20170219/08107c619405c9ba0c3e1285d2e65057.jpg
I'm using a Savage Axis in .223 Remington. It is a 1-9 twist.
The data is from Hodgdon. I'll let you know how it goes.


Sent from my iPhone using Tapatalk

[Hersh5317]

I appreciate that, I was looking for heavier bullets at the same speed. I am sure some of the SP bullets I could load up with Trail Boss too. I saw that one though. Hodgdon is in my favorites tab :)

[andyknaster]

I appreciate that, I was looking for heavier bullets at the same speed. I am sure some of the SP bullets I could load up with Trail Boss too. I saw that one though. Hodgdon is in my favorites tab :)

I've seen people post Trail Boss loads in .223 up to 6gr. With a heavier bullet, you could try walking your way up from 4 to 6.


Sent from my iPhone using Tapatalk

[Mountain Man]

Try loading the 62gr M855 PENETRATOR backwards. Did that in a couple AR type guns with decent success. Those bullets are pretty cheap from surplus sources and they will actually open up on impact since the ass end (now the nose if loaded backwards) of the projectile is not fully jacketed. Trailboss is good stuff. I don't think you can force enough of it into a 223 case to come anywhere near pressure issues

Sent from my A571VL using Tapatalk

[Hersh5317]

I loaded up some 52 Berger and 55 Vmax both over 4gr of Trailboss (only 10 each in case I need to pull them).. I want to develop this load for close range plinking and small game. With that in mind, I want varmint style bullets or an OTM that I might shorten a little to expand the "HP". I will do some experimenting, but do not want to load anything backwards at this point.

[Mountain Man]

Just a suggestion. You can actually drill a little bit of the back end in until you hit the steel portion and up the expansion factor quite a bit as well. I would check out Lyman data for cast 223 loads, iirc they had a few starting loads that were down around 1000 fps. Lyman makes a steel mold that drops 2 of them with every pour. Big flat nose profile bullet. Did pretty well out of my 9" twist AR platforms at low speeds. I did a similar project with my .30-06 shooting 100 grain half jackets over 5 gr of bullseye. Had to drill the flash holes to 1/8" for uniform velocity but it made a great 50yd grouse load that wouldn't scare off any big game nearby.

Sent from my A571VL using Tapatalk

[Hersh5317]

A 30 cal project is on the to do list, maybe a 300 Blk, 32-20, 30 Badger, or the like. I would love a 6.5TCU as well. One project at a time.

[darkker]

What is the heaviest bullet you have been able to stabilize in a 1:9 loaded to about 1k fps? If you are comfortable sharing the load data, please do so. I am curious to see as I had intended to build a fast twist Hornet for such applications, but was told it would be easier to do with a .223 due to brass life and availability. The heaviest/longest I have is 55 Vmax, but wonder if the 60 Vmax, or any of the 68/69 grainers would stabilize at subsonic speeds in my 22" 1:9.
Not likely, but remember stability is about length, not weight. MV * 720 / Twist = RPM
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi
JBM will let you look up lengths, then plug-in your specifics for an idea.

[andyknaster]

Not likely, but remember stability is about length, not weight. MV * 720 / Twist = RPM
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi
JBM will let you look up lengths, then plug-in your specifics for an idea.

The JBM states that you enter the overall length of the bullet, but the entire length of the bullet does not engage with the rifling. So in a standard bullet, would the distance be from the base to the ogive and in a boat tail bullet from the end of the boat tail taper to the ogive? Neither the boat tail nor ogive engage with the rifling.


Sent from my iPhone using Tapatalk

[Hersh5317]

Total length has to stabilize, so use that. I am thinking of trying some 63gr SMPs for loads too. So many choices to mess with for different purposes.

[andyknaster]

Total length has to stabilize, so use that. I am thinking of trying some 63gr SMPs for loads too. So many choices to mess with for different purposes.

Ok. To be honest, I just take the data I'm presented and use it. I'm sure that folks doing long range gunnery need to have a grasp of this. I'm just a recreational shooter trying to save some money by rolling my own.


Sent from my iPhone using Tapatalk

[Hersh5317]

Me too as far as a recreational shooter, but I have spent more money on equipment and gas to and from the range than before I started reloading. I have no complaints though, and am trying to learn as much as possible.

[darkker]

The JBM states that you enter the overall length of the bullet, but the entire length of the bullet does not engage with the rifling. So in a standard bullet, would the distance be from the base to the ogive and in a boat tail bullet from the end of the boat tail taper to the ogive? Neither the boat tail nor ogive engage with the rifling.


Sent from my iPhone using Tapatalk
As Hersh said, it's the total length that needs stabilized so use that. On the left hand side of the JBM page there is a "Lengths" tab, click on that and they have most of the bullet lengths listed.